It is well known in the livestock industry to apply insecticide impregnated ear tags to livestock to control biting and nuisance flies, and other ectoparasites. To meet efficacy standards, it is generally necessary to apply an insecticide ear tag to each ear of the animal. An example of a known insecticide tag is shown in U.S. Pat. No. 4,581,834.
It is equally well known in the livestock industry to apply identification ear tags to livestock. So-called ID tags have been used not only to identify the owner of an animal, but now more commonly to identify a particular animal. ID tags therefore make it possible to not only maintain a record of the life of an individual animal, such as its history of disease, vaccination, etc., but also to enable tracking of meat from the livestock producer to the meat counter and back to the individual animal. ID tagging of livestock has thus become critically important to the regulatory control of the food supply.
Commercial ID tags are typically available in two different forms: as a two-piece tag of the type shown in the aforementioned U.S. Pat. No. 4,581,834, or as a so-called one-piece tag, as shown for example in U.S. Pat. No. 5,228,224. In each instance, the tag is installed in the ear of an animal with an applicator by creating a hole in the ear of the animal.
Recent European Union regulations requiring ID ear tags also specify that only one hole can be placed in each ear of the animal. Consequently, it is no longer permitted in Europe to install an ID tag and a separate insecticide tag in each ear of an animal. In addition, there is a growing reluctance on the part of livestock producers in general to apply two tags to one ear of an animal.
Previous attempts have been made to add an insecticide carrying component to an ID ear tag. For example, U.S. Pat. No. 4,428,327 describes a two-piece ID tag having a rectangular insecticide impregnated member that is secured to the bottom portion of the flat identification area of the tag. Optionally, a second insecticide impregnated member can be secured to the opposite side of the ID tag as well.
Long term retention of the insecticide members on the ID tag is problematic with designs of this type. Moreover, because only one side of the insecticide member is exposed, less insecticide is transferred to the animal. In addition, it is not practical with this known design to replace the insecticide member(s) in a way that will facilitate reliable retention of the replacement insecticide member(s) on the ID tag. As a result, combination tags of this type have not been widely commercialized.
A second prior art combination insecticide-ID tag is shown in U.S. Pat. No. 4,366,777, which discloses a one-piece ID tag having a separately attachable collar member, comprising an insecticide reservoir, that is wrapped around the neck portion of the ID tag. As the two ends of the collar member are designed to be adhesively secured to one another, long term retention of the insecticide reservoir on the ID tag is also clearly a problem with this known design. In addition, very limited surface area is provided on the insecticide reservoir, thus compromising the time period over which proper efficacy of the insecticide can be maintained.
A further combination tag is disclosed in U.S. Pat. No. 4,612,877. A first embodiment of the combination tag shown in this patent comprises a one-piece ID tag having an elongated dove-tail channel formed on the backside of the panel portion of the tag for slidingly receiving an insecticide tag member having a correspondingly-shaped attachment rib. A second embodiment shows a one-piece ID tag having a slot formed in the neck portion of the tag for receiving an enlarged arrow-shaped attachment head portion of an insecticide member. In both embodiments, long term retention of the insecticide member on the ID tag is problematic, due to the relative softness of the plastic material required for carrying insecticide, which makes it highly likely that the insecticide member will be ripped or torn from the tag when the animal rubs its head against its body or against other objects.
Lastly, U.S. Pat. No. 4,059,074 shows a one-piece ID tag having a disc-shaped insecticide carrier coupled to the stem portion of the tag. The circular insecticide disk has a central hole for receiving the stem of the tag and a slot extending radially from the central hole to the outer perimeter of the disk to enable the insecticide disk to be slipped over the stem for attachment to the tag. However, as noted above, due to the relative softness of the plastic material required to carry the insecticide, it is readily apparent the illustrated circular insecticide disk is susceptible to becoming separated from the ID tag in the same manner in which it is installed; namely by the stem of the tag slipping back through the radial slot in the disk.
Consequently, there is a commercial need for an alternative solution to the conventional insecticide ear tag.